two. these are the pictures that came outovernight.tamerlantsarnaev.number two on the loose, a fugitive right now, believed to be armed and dangerous, described as a terrorist, he was caught on camera last night, he's been on the loose for several hours and all of boston, the entire city of boston surrounding suburbs in lockdown right now. >> that's right. abc news just spoke to those boys' father, he is in shock and implores his son to himself up. he told abc news, he said that he think his sons were set up and he said they were very nice kids, never touched explosives and never learned how to handle weapons. he said that his younger son is on the run and in hiding because he's also afraid, words from his father. never saw indication at all atwas capable of violence. we're reminded by brad garrett, our fbi specialing at, often these terrorist lead double lives. we begin with chief investigative brian ross, on the ground, all through the night in watertown, brian, a night of gunfire, bombs, police hunting down the terrorists right now. >> reporter: indeed, george. he was las

arrest. his older brother,6-year-oldtamerlanwaskilled in a shootout with the police hours earlier. >> many groups, the cia, defense department included, want to question the suspect. there are burning questions about why the brother allegedly launched the attack and whether they're attached to a larger conspiracy. >> our abc news team is out in full force. we start with chief investigative correspondent brian ross, who has been on this story from the jump. he has a ploe-by-blow account of how the arrest went down. >> reporter: the capture was dramatic and quick. authorities said they brought justice to the victims of the marathon bombings and turned despair into delight. >> we are internally gre e tern the outcome. >> reporter: just 25 minutes after the lockdown was lifted, a water town resident went out to walk his dog and noticed blood on the side of his boat. >> he looked in and saw man covered in blood. he retreated and called us. >> reporter: police and the fbi roared back into town. a helicopter with infrared sensors detected movement in the boat. >> we're getting informatio